USGS WPhase Moment Solution

COSTA RICA

12/ 9/ 8 20:29:32.00

Epicenter:  10.095  -85.321
MW 5.7

USGS/WPHASE CENTROID MOMENT TENSOR
12/ 9/ 8 20:29:32.00
Centroid:    9.995  -85.422
Depth  19         No. of sta: 29
Moment Tensor;   Scale 10**17 Nm
  Mrr= 2.24       Mtt=-1.40
  Mpp=-0.84       Mrt= 3.32
  Mrp=-0.93       Mtp= 0.79
 Principal axes:
  T  Val=  4.24  Plg=59  Azm=  9
  N     = -0.42       6      110
  P     = -3.82      29      204

Best Double Couple:Mo=4.0*10**17
 NP1:Strike=314 Dip=17 Slip= 114
 NP2:       109     75        83

Moment Tensor Solution
The figure above shows a visual representation of the style of faulting (focal mechanism) derived from the estimated moment tensor. Shaded areas show quadrants of the focal sphere in which the P-wave first-motions are away from the source, and unshaded areas show quadrants in which the P-wave first-motions are toward the source. The dots represent the axis of maximum compressional strain (in black, called the "P-axis") and the axis of maximum extensional strain (in white, called the "T-axis") resulting from the earthquake.

Moment Tensor Solution

Details on the W-phase inversion algorithm.